I have not much knowledge about it but a used sewing machine would be an excellent frugal way to go. You should take a variety of samples to sew on including old jeans to hem or a similar heavy fabric.Hope this helps every one .
Personally I don't know, but I think the best thing to do is to ask someone who is selling them as they can recommend you a good one to start off with. If you're in the UK, John Lewis have a decent selection and they normally have at least one person selling the machines who can sew, and they can even show you how to use the machine